assignment: To construct a press-fit kit using either the laser
cutter or the vinyl cutter.
details: For this project I developed three designs. The first,
and most straightforward, was a simple 3D press-fit construction
kit using a single primitive shape. I designed the shape in OODraw
without introducing any additional processing tollerance under the
assumption that I could make the necessary adjustments in the cam.py
application. My intial attempt, using colored 1/8" acrylic and the
recommended settings proved ill-fitting. On my next iteration, I
increased the contour offset from .00 to .01 and the pieces seemed
to fit together well. When I took the shapes home and tried
assembing them though I discovered that there was more variablity
in the shapes than I had expected, resulting in a number of broken
pieces. I returned to the lab and cut more pieces with roughly the
same result. It was only upon inspection of the burn patterns on the
cut pieces that I realized that the material was warping during
cutting, resulting in the variation I saw in my shapes. Fortunately
I had enough well-fitting shapes to construct the simple model
depicted below. In general though it seems that acrylic tends to warp
under laser cutting and some measure might need to be taken to
ensure that the acrylic remains flat during cutting.
->OODraw .sxd file of construction kit
My next design was a press-fit acrylic bike chain. The idea was to
introduce rotational motion into an object built from 2-D pieces.
With any luck I'll get this thing cut in the next few hours.
->OODraw .sxd file of chain
My final design was a belt, again exploring the idea of introducing
free rotation into an object built up entirely from 2-D peices.
Additionally, this belt would include a crude latching mechanism
the functioning of which will depend upon the flexiblity of the
arcylic material.
->OODraw .sxd file of belt